What is the Role of PCB Solder Mask Opening Window

What is the role of PCB solder mask opening?

Before understanding what PCB solder mask opening is, let us first learn what solder mask specifically refers to! The so-called PCB solder mask refers to the printed circuit board On the part that needs to be painted with green oil, the PCB solder mask window means that the copper skin on the pad cannot be covered by the solder mask ink, but must leak out of the board, as shown in the following figure:

What is the function of the PCB solder mask window?

If it is a double-sided circuit board in the design, there will be a solder mask layer printed on both sides of the board. The function of this layer of ink is to prevent oxidation of the circuit board and protect it, and facilitate subsequent SMT soldering. , PCB solder mask opening means that the copper skin around the aperture of the circuit board must not be covered by ink. If the solder mask is covered, it will not be possible to measure the corresponding signal. Only by leaking the copper skin of the aperture to the surface can it effectively increase the distance. The wire thickness increases the passing current limit.

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